Nozzle for fuel injector system



Oct. 25, 1960 .1. F. ARMSTRONG NOZZLE FOR FUEL INJECTOR SYSTEM Filed March 14, 1957 a G u u H w 6 3 Wm 2 3 MM 2 M w 1 9 z 0 2 2 8 H 2 m m a z w INVENTOR. JAMES FRED ARMSTRONG ATTORNEY Patented Oct. 25, 1960 NOZZLE FOR FUEL INJECTOR SYSTEM James F. Armstrong, St. Louis, Mo., assignor to ACE Industries, Incorporated, New York, N.Y., a corporation of New Jersey Filed Mar. 14, 1957, Ser. No. 646,063

1 Claim. (31. 239-533 This invention relates to nozzles for discharging fuel adjacent the intake port of an internal combustion engine, and more particularly to a fuel nozzle adapted for use with a fuel flow metering and distributing system such as shown in my prior applications, Serial No. 516,358, filed June 20, 1955, for Injection Carburetion, now Patent 2,785,669 of Mar. 19, 1957; Serial No. 622,917, filed Nov. 19, 1956, for Fuel Injection System, now Patent 2,876,758 of Mar. 10, 1959; and Serial No. 632,798, filed Ian. 7, 1957, for Fuel Injection System.

Heretofore, difiiculty has been experienced in obtaining uniformity in operation between a plurality of these nozzles. Engine operation indicated malfunctioning and unequal fuel distribution. On examination, it was determined that the cause could be traced directly to nozzle valve design and construction.

In order for the nozzles to perform the necessary function of Pressure regulation, the construction must permit free valve travel in response to slight pressure differentials acting on the diaphragm operating the valve. Because both valve and seat are of metal, perfect alignment and surface finish is required to prevent leakage. This is almost impossible to obtain except by exacting machine operations.

It is the object of this invention to eliminate binding in the valve operating mechanism, and to modify the valve action to limit the magnitude of the actuating forces to eliminate the necessity of metal in both the valve and seat.

According to the present invention, the valve and the diaphragm operated stem for the valve are constructed in two pieces and a connection is provided between the two to allow the valve to have a self-centering action independent of the stem so that the valve may freely travel within its guide.

According to the present invention, the flexible connection between the diaphragm operated stem and the valve is constructed in such a way, with relation to the operating diaphragm, as to limit the maximum force imposed on the valve by the stem, so that it becomes possible to use a softer material, such as a plastic material, as a valve seat, without so deforming the plastic material as to close the nozzle discharge passage by excessively heavy forces transmitted from the diaphragm to force the valve into the softer seat material.

The accompanying drawings illustrate one manner contemplated for carrying out the invention.

In the drawings,

Fig. 1 is a view in vertical elevation with parts broken away to illustrate their position when the nozzle valve is closed.

Fig. 2 is a view in vertical elevation with parts broken away to illustrate their position when the nozzle valve is open.

Figs. 3 to are fragmentary elevational views in section showing the details of the nozzle valve on a greatly enlarged scale.

Referring now to the drawings, the body of the nozzle 1 is a hollow casting having a cavity 2 apertured at 3 to receive a threaded bushing 4 which, in turn, is internally threaded at 5 to secure the nozzle stem 6 within the aperture 3 of the body casting.

The open end of the body casting 1 has a wide shoulder 7 surrounded by a narrow flange 8. Integral with the body casting 1 is a boss 10 threaded at 11 to form a fluid pressure connection with the charging fuel line which connects with the fuel metering means of my prior invention. A passage 12 connects between the cavity 2 and the hollow boss 10.

Secured on the flange 8 is a cap 14 provided with a plurality of screw holes for'attaching screws 15 secured in tapped holes in the flange 8 (not shown). Cap 14 has a shallow cavity 16 and a centrally located cylindrical recess 17. Cast integrally with the cap 14 is a hollow boss 18 threaded at 19 to form a fluid pressure connection with a datum pressure system as described in my prior application. The cavity 16 is surrounded by a narrow flange 20.

The operating diaphragm 22 is secured between the two flanges 20 and 8, and is a movable wall forming two expansible chambers of cavities 2 and 12. Connected with the diaphragm is a diaphragm stem 23 which is secured to the diaphragm by a pair of backing plates 24 and 25 clamped together by nuts 26 and 27 threaded on the stem 23.

The travel of the diaphragm Within the cavities 2 and 16 is limited in a valve closing direction by circumferentially extending flange 29 and semi-circular bead 30 on the backing plate 25. Within the cavity 17 is a spring 31 which urges the stem 23 in a valve closing direction.

The lower end of valve stem 6 is internally threaded at 33 to receive the valve guide 34. Within the valve guide 34 is an upwardly facing seat 35 surrounding a nozzle 36, all as shown in Figs. 3, 4 and 5.

The needle valve 38 has vertical ribs 39 cooperating with the internal guide surface formed on the element 34 and, in addition, a valve end 40 which cooperates with the seat 35.

At the upper end, valve 38 has a short stem 42 which is frictionally engaged by a spring 43. The opposite end of the spring 43 engages the reduced end 44 formed on the valve operating stem 23 and abuts against a shoulder thereon. Spring 43 is a flexible two-way connection between the parts 42 and 23.

The valve guide 34 is preferably formed with a seat 35 having insert 46 formed of Teflon, upon which the valve 40 operates. This forms a leak-proof valve and seat combination which is gasoline-tight under light pressure and in spite of slight misalignment.

As shown in Figs. 3 to 5, inclusive, the valve is operated on and off of its seat by movements of the stem 23 through a flexible and resilient connection in the form of a spring 43 which permits the valve element 38 to be guided in the valve seat without interference from misalignment between the 'valve and its operating stem 23.

The spring 43 is relatively stifi and closely wound, forming a relatively solid connection between the stem and the valve 38 in the direction of valve movement. The stem and the valve move together so that the valve operates the same as if the stem were positively connected to the valve by a universal joint. In the open end of the threaded nipple 3 is a guide 50 for the stem 23.

Operation The stem is operated through the guide 50 by movements of the diaphragm 22 in response to differences in fluid pressure acting on opposite sides thereof. Movement of the diaphragm in a valve closing direction is limited, however, by engagement of the head 30 and the flange 29 with the shoulder 7 in the cavity of the body 1, so that, in the fully closed position as illustrated in Fig. 3, the spring 43 is compressed but is not collapsed solid. Thus, the pressure of the valve 40 on its seat insert 46 bears no relation to. the difference in force produced .by pressures acting on opposite sides of the diaphragm 22. Consequently, excessive forces in a valve closing direction cannot be transmitted which would distort the plastic valve seat insert 46 and cause it to close the nozzle 36.

Fig. 4 illustrates the position of the parts as the valve 40 starts to lift. from its seat insert 46. In this position the spring 43 has expanded only slightly, illustrating the fact that the pressure of the valve on the seat as illustrated in Fig. 3 is relatively light.

When the valve moves to the position shown in Fig. 5, it is fully opened, and fuel passes down between the stem 23 and the tube 6, between the guides 39, and out of the nozzle 36.

A structure has been described which will fulfill all the objects of the invention as set forth above, but it is contemplated that other modifications will occur to those skilled in the art, which modifications come within the scope of the appended claim.

I claim:

A pressure regulating type of fuel nozzle for an internal combustion engine fuel charging system of the pressure type comprising, a discharge nozzle having a passage with axial aligned inlet and outlet openings, the outlet opening having a valve seat, a fluid pressure connected to said inlet opening, reciprocating valve means controlling the outlet opening said valve means comprising a valve member and a valve operating member with an intermediate resilient compressible means, said valve means being guided for movement towards and from the valve seat by said passage in the nozzle, and fluid actuated means secured to said valve operating memher for sequentially actuating the valve operating member thus applying pressure to the resilient compressible means and such means in turn actuating said valve memher to press said valve member against the valve seat with a predetermined pressure as controlled by the intermediate resilient compressible means.

References Cited in the file of this patent UNITED STATES PATENTS 

